With the development of modern science and technology and the improvement of people's living standards, more and more people take a driving test, and driver training for the driving test is indispensable. For a driving exam that uses a traditional method, a powerful reference station is set up at a relatively higher place and a mobile station is installed on a training vehicle. The reference station sends differential data through a radio station, and the mobile station receives the differential data through the radio station, so as to carry out RTK resolving and obtain a fixed solution of the positioning state. After that, positioning information with centimeter-level positioning accuracy can be obtained. However, when more than one reference station is used at the same site, it is very easy to cause crosstalk. Moreover, when the field is large enough, floating solution of the positioning state will occur in the region out of the transmission range of the radio station. In this case, the positioning accuracy is of meter level, which will affect the accuracy of judgment in the training and examination.